Background: Simulated disaster is increasingly popular as an educational tool. Real-world response to disaster is known to cause psychological trauma, but little is known about the psychological effects of simulated disaster response. The World Health Organization-5 (WHO-5) well-being index is a brief, validated screening tool for wellbeing and depression risk. This study was designed to evaluate the effect of simulated disaster on well-being using the WHO-5. Methods:As part of an annual series of community-based disaster response simulation events, volunteers including community members, healthcare professionals and medical students were screened using the WHO-5 well-being index. Rates of well-being and depression risk were compared to national averages. Poor well-being was defined as a total score of ≤ 13 or 0 or 1 on any question. Results:A total of 29 (21 medical students) and 114 (19 medical students) individuals completed the survey after two separate events. Poor well-being was found in 24.1% (N=7) and 24.6% (N=28) of all responders and 23.8% (N=5) and 10.5% (N=2) of the medical student cohort after the preload and event, respectively. Majority age for total cohort (N=139) was between19-60 (93%) and 63% (N=88) were female. Conclusion:A minority of participants reported poor well-being in realistic disaster-simulation. However, community-based simulation exercises should increasingly consider well-being to ensure safety of training environments.